Mug decoration



FIG. 1 is a left side view of a mug decoration showing my new design;

FIG. 2 is a rear view of the mug decoration of FIG. 1;

FIG. 3 is a front view of the mug decoration of FIG. 1; and,

FIG. 4 is a right side view of the mug decoration of FIG. 1.

The broken line showing of a mug in FIGS. 1-4 is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a mug decoration, as shown and described. 